Combination catalytic converter and filter

Abstract

A combination catalytic converter and filter ( 10 ) for internal combustion engine exhaust is provided by a single unitary flow member having an upstream frontside ( 14 ) and a downstream backside ( 16 ). The member has a plurality of flow channels ( 18 ) extending axially from the upstream frontside to the downstream backside. Each channel has left and right sidewalls ( 20 and 22 ) formed by pleated filter media ( 24 ), and top and bottom walls formed by respective upper and lower boundary layers ( 26 and 28 ). The left and right sidewalls ( 20 and 22 ) extend axially continuously from the upstream frontside to the downstream backside. The sidewalls ( 20 and 22 ) have first upstream sections ( 30, 32 ) proximate the upstream frontside ( 14 ), and second downstream sections ( 34, 36 ) proximate the downstream backside ( 16 ). One of the sections is a catalytic section ( 33 ) treated with a catalyst for the exhaust. The other of the sections is a filter section ( 35 ) having axially spaced alternately blocking sealants ( 38, 40 ) in alternate channels ( 48, 44 ) such that exhaust must pass through the pleated filter media ( 24 ). The catalytic section may be upstream or downstream of the filter section. A filter section may be nested axially between two catalytic sections, as well as other combinations and sequencing. The filter section may additionally be treated with catalyst.

What is claimed is:  
     
       1. A combination catalytic converter and filter for internal combustion engine exhaust comprising in a single unitary member pleated filter media and upper and lower boundary layers defining a plurality of axially extending flow channels having first and second serially sequential axial sections, one of said first and second sections being a catalytic section treated with a catalyst for said exhaust, the other of said first and second sections being a filter section with alternately sealed said channels forcing exhaust to flow through said pleated filter media, wherein said channels extend axially from upstream to downstream, said first section having a first upstream end and a first downstream end, said second section having a second upstream end and a second downstream end, said second upstream end being axially contiguous to and forming an axial junction with said first downstream end, wherein exhaust flows axially from said first upstream end then to said axial junction then axially to said second downstream end, and wherein said filter section is formed between axially spaced first and second sets of alternating blocking sealants in said channels, said first set of sealants being at said axial junction, said second set of sealants being at one of said second downstream end and said first upstream end, said first set of sealants being axially spaced between said first upstream end and said second downstream end. 
     
     
       2. The invention according to  claim 1  wherein said first set of sealants is axially spaced downstream from said first upstream end by said first section therebetween, and said first set of sealants is axially spaced upstream from said second downstream end by said second section therebetween. 
     
     
       3. The invention according to  claim 2  wherein said catalytic section is upstream of said filter section. 
     
     
       4. The invention according to  claim 2  wherein said filter section is upstream of said catalytic section. 
     
     
       5. The invention according to  claim 2  further comprising in combination a third serially sequential axial section, said second section being nested between said first and third sections in axial alignment therewith. 
     
     
       6. The invention according to  claim 5  wherein said first and third sections are catalytic sections, and said second section is a filter section. 
     
     
       7. The invention according to  claim 2  wherein said first section is said catalytic section, said second section is said filter section, said first section is upstream of said second section, said first set of alternating blocking sealants is at the upstream end of said filter section, said second set of alternating blocking sealants is at the downstream end of said filter section. 
     
     
       8. The invention according to  claim 2  wherein said filter section is treated with catalyst. 
     
     
       9. The invention according to  claim 2  wherein said upper and lower boundary layers are formed by a single layer in a spiral wrap. 
     
     
       10. A combination catalytic converter and filter for internal combustion engine exhaust comprising a single unitary flow member having an upstream side and a downstream side, said member having a plurality of flow channels extending axially from said upstream side to said downstream side, each channel having left and right sidewalls formed by pleated filter media, and top and bottom walls formed by respective upper and lower boundary layers, said left and right sidewalls extending axially continuously from said upstream side to said downstream side, said sidewalls having first upstream sections proximate said upstream side, said sidewalls having second downstream sections proximate said downstream side, one of said first and second sections being a catalytic section treated with a catalyst for said exhaust, the other of said first and second sections being a filter section and having axially spaced alternately blocking sealants in alternate said channels such that exhaust must flow through said pleated filter media, wherein said channels extend axially from upstream to downstream, said first section having a first upstream end and a first downstream end, said second section having a second upstream end and a second downstream end, said second upstream end being axially contiguous to and forming an axial junction with said first downstream end, wherein exhaust gas flows axially from said first upstream end then to said axial junction then axially to said second downstream end, and wherein said filter section is formed between axially spaced first and second sets of said alternating blocking sealants in said channels, said first set of sealants being at said axial junction, said second set of sealants being at one of said second downstream end and said first upstream end, said first set of sealants being axially spaced between said first upstream end and said second downstream end. 
     
     
       11. The invention according to  claim 10  wherein said first set of sealants is axially spaced downstream from said first upstream end by said first section therebetween, and said first set of sealants is axially spaced upstream from said second downstream end by said second section therebetween. 
     
     
       12. The invention according the  claim 11  wherein said sidewalls of said catalytic section are perforated such that exhaust flows through said catalytic section along a first set of alternate channels axially rectilinearly aligned with a first set of alternate channels in said filter section, and exhaust flows through said catalytic section along a second set of alternate channels laterally offset from said first set of channels and communicating therewith through said perforations, such that exhaust flows through all of the channels of said catalytic section, increasing surface area for catalytic activity, notwithstanding said alternating blocking sealants in said filter section. 
     
     
       13. The invention according to  claim 11  wherein said sidewalls have third downstream sections downstream of said second sections, said second sections being nested between in axial alignment with said first and third sections, each of said left and right sidewalls of each channel extending axially rectilinearly from said first section to said second section to said third section, maintaining exact axial alignment of the respective said channel. 
     
     
       14. The invention according to  claim 13  wherein said first and third sections are catalytic sections, and said second section is a filter section. 
     
     
       15. The invention according to  claim 11  wherein said filter section is treated with catalyst. 
     
     
       16. The invention according to  claim 11  wherein said upper and lower boundary layers are formed by a single layer in a spiral wrap. 
     
     
       17. A combination catalytic converter and filter for internal combustion engine exhaust comprising a single unitary flow member having an upstream side and a downstream side, said member having a plurality of flow channels extending axially from said upstream side to said downstream side, each channel having left and right sidewalls formed by pleated filter media, and top and bottom walls formed by respective upper and lower boundary layers, said left and right sidewalls extending axially continuously from said upstream side to said downstream side, said sidewalls having first upstream sections proximate said upstream side, said sidewalls having second downstream sections proximate said downstream side, one of said first and second sections being a catalytic section treated with a catalyst for said exhaust, the other of said first and second sections being a filter section and having axially spaced alternately blocking sealants in alternate said channels such that exhaust must flow through said pleated filter media, wherein said sidewalls of said catalytic section are perforated such that exhaust flows through said catalytic section along a first set of alternate channels axially rectilinearly aligned with a first set of alternate channels in said filter section, and exhaust flows through said catalytic section along a second set of alternate channels laterally offset from said first set of channels and communicating therewith through said perforations, such that exhaust flows through all of the channels of said catalytic section, increasing surface area for catalytic activity, notwithstanding said alternating blocking sealants in said filter section, and wherein: 
       said catalytic section is axially upstream of said filter section;  
       said axially spaced alternating blocking sealants comprise a first set of alternating blocking sealants at the upstream end of said filter section and a second set of alternating blocking sealants at the downstream end of said filter section;  
       said first set of alternate channels in said catalytic section are open at their downstream ends, and exhaust flows rectilinearly from said first set of channels in said catalytic section to said first set of channels in said filter section, the downstream ends of said first set of channels in said filter section being blocked by said second set of said alternating blocking sealants;  
       said second set of alternate channels in said catalytic section are blocked at their downstream end by said first set of said alternating blocking sealants in the upstream ends of a second set of alternate channels in said filter section;  
       said perforations are upstream of said first set of alternating blocking sealants, such that exhaust flows axially along said second set of channels in said catalytic section and then laterally through said perforations and joins said flow in said first set of channels in said catalytic section flowing axially rectilinearly into said first set of channels in said filter section.  
     
     
       18. A combination catalytic converter and filter for internal combustion engine exhaust comprising a single unitary flow member having an upstream side and a downstream side, said member having a plurality of flow channels extending axially from said upstream side to said downstream side, each channel having left and right sidewalls formed by pleated filter media, and top and bottom walls formed by respective upper and lower boundary layers, said left and right sidewalls extending axially continuously from said upstream side to said downstream side, said sidewalls having first upstream sections proximate said upstream side, said sidewalls having second downstream sections proximate said downstream side, one of said first and second sections being a catalytic section treated with a catalyst for said exhaust, the other of said first and second sections being a filter section and having axially spaced alternately blocking sealants in alternate said channels such that exhaust must flow through said pleated filter media, wherein said sidewalls of said catalytic section are perforated such that exhaust flows through said catalytic section along a first set of alternate channels axially rectilinearly aligned with a first set of alternate channels in said filter section, and exhaust flows through said catalytic section along a second set of alternate channels laterally offset from said first set of channels and communicating therewith through said perforations, such that exhaust flows through all of the channels of said catalytic section, increasing surface area for catalytic activity, notwithstanding said alternating blocking sealants in said filter section, and wherein: 
       said filter section is axially upstream of said catalytic section;  
       said axially spaced alternating blocking sealants comprise a first set of alternating blocking sealants at the upstream end of said filter section and a second set of alternating blocking sealants at the downstream end of said filter section;  
       said first set of alternate channels in said catalytic section are open at their upstream ends, and exhaust flows rectilinearly from said first set of channels in said filter section to said first set of channels in said catalytic section, the upstream ends of said first set of channels in said filter section being blocked by said first set of said alternating blocking sealants;  
       said second set of alternate channels in said catalytic section are blocked at their upstream end by said second set of alternating blocking sealants in the downstream ends of said second set of alternate channels in said filter section;  
       said perforations are downstream of said second set of alternating blocking sealants, such that exhaust flows axially along said first set of channels in said filter section and then some of the exhaust flows laterally through said perforations and then flows axially rectilinearly along said second set of channels in said catalytic section.  
     
     
       19. A combination catalytic converter and filter for internal combustion engine exhaust comprising a single unitary flow member having an upstream side and a downstream side, said member having a plurality of flow channels extending axially from said upstream side to said downstream side, each channel having left and right sidewalls formed by pleated filter media, and top and bottom walls formed by respective upper and lower boundary layers, said left and right sidewalls extending axially continuously from said upstream side to said downstream side, said sidewalls having first upstream sections proximate said upstream side, said sidewalls having second downstream sections proximate said downstream side, one of said first and second sections being a catalytic section treated with a catalyst for said exhaust, the other of said first and second sections being a filter section and having axially spaced alternately blocking sealants in alternate said channels such that exhaust must flow through said pleated filter media, wherein each of said left and right sidewalls of each channel extends axially rectilinearly from said first section to said second section, maintaining exact axial alignment of the respective said channel including the catalyzing and filtering sections thereof, wherein said sidewalls have third downstream sections downstream of said second sections, said second sections being nested between in axial alignment with said first and third sections, each of said left and right sidewalls of each channel extending axially rectilinearly from said first section to said second section to said third section, maintaining exact axial alignment of the respective said channel, wherein said first and third sections are catalytic sections, and said second section is a filter section, and wherein said sidewalls of said first and third catalytic sections are perforated such that exhaust flows through said first catalytic section along a first set of alternate channels axially rectilinearly aligned with a first set of alternate channels in said second filter section, and exhaust flows through said first catalytic section along a second set of alternate channels laterally offset from said first set of channels and communicating therewith through said perforations, such that exhaust flows through all of the channels of said first catalytic section, increasing surface area for catalytic activity, notwithstanding said alternating blocking sealants in said second filter section, and exhaust flows from a second set of alternate channels in said second filter section rectilinearly aligned with a first set of alternate channels in said third catalytic section, and exhaust also flows from said second set of channels in said second filter section through said perforations in said sidewalls of said third catalytic section and then axially along a second set of alternate channels in said third catalytic section, such that exhaust flows through all of the channels in said third catalytic section, increasing surface area for catalytic activity, notwithstanding said alternating blocking sealants in said second filter section.